EP0720873B1 - Procédé de revêtement par extrusion - Google Patents

Procédé de revêtement par extrusion Download PDF

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Publication number
EP0720873B1
EP0720873B1 EP96300063A EP96300063A EP0720873B1 EP 0720873 B1 EP0720873 B1 EP 0720873B1 EP 96300063 A EP96300063 A EP 96300063A EP 96300063 A EP96300063 A EP 96300063A EP 0720873 B1 EP0720873 B1 EP 0720873B1
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EP
European Patent Office
Prior art keywords
coating composition
coating
die
extrusion die
extrusion
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP96300063A
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German (de)
English (en)
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EP0720873A3 (fr
EP0720873A2 (fr
Inventor
Alfred H. Willnow
Kent J. Evans
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Xerox Corp
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Xerox Corp
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Publication of EP0720873A3 publication Critical patent/EP0720873A3/fr
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • B05D1/265—Extrusion coatings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
    • B05C5/0254—Coating heads with slot-shaped outlet

Definitions

  • This invention relates to a process for applying a coating of pigment particles in a film-forming binder by extrusion coating techniques.
  • the extrusion die For fabrication of web type, flexible electrophotographic imaging members, the extrusion die must lay down very thin coatings meeting extremely precise, critical tolerances in the single or double digit micrometer ranges. Moreover, a plurality of dies may be needed to lay down up to three extruded coatings conventionally employed for flexible electrophotographic imaging members.
  • the flexible electrophotographic imaging members may also comprise additional coatings applied by non-extrusion coating techniques so that the finished electrophotographic imaging member can contain as many as 5 different coatings.
  • the extrusion die usually comprises spaced walls, each having a surface facing each other.
  • a coating composition is supplied by a reservoir through an inlet to a manifold that feeds the coating composition to one side of the passageway and the coating composition travels through the passageway to an exit slot on the side of the passageway opposite the reservoir.
  • Dams are provided at opposite ends of the passageway to confine the coating composition within the passageway as the coating travels from the reservoir to the exit slot.
  • US-A-5,273,583 describes an apparatus for the continuous coating of charge transport solutions onto a substrate to form an electrophotographic imaging member, including a pump to a flow of a first highly doped charge transport solution and a pump to a flow of a second undoped or lowly doped charge transport solution at predetermined rates to a common junction at which the flows intermix into a common flow upon contacting each other; piping connecting the pumping means to the common junction; and mixing device associated with the junction for continuously mixing the common flow during its movement through the mixing device, the mixing device having a short spiral flow path of less than about 200 cm for the solutions sufficient to substantially complete mix the common flow during its movement through the mixing means.
  • US-A-3,227,136 discloses an extrusion coating apparatus especially intended for use in the manufacture of a magnetic tape of the type wherein a dispersion of magnetic particles in a suitable binder is coated on the surface of a carrier web or strip.
  • Figure 1 of US-A-3,227,136 shows an extrusion coating apparatus combined with a circulating system which is used in order to store the dispersion of the magnetic particles prior to extrusion coating.
  • the size of the conduits in the circulating system is preferably such that the dispersion is maintained throughout the circulating system under relatively high shear conditions of about 200 s -1 .
  • the present invention provides a process for forming a coating from a flocculating coating composition comprising pigment particles dispersed in a solution of a film-forming binder dissolved in a fugitive liquid carrier, maintaining said coating composition in turbulent flow under average shear conditions of at least 10 s -1 while transporting said coating composition through an inlet (52) of an extrusion die (50), through a manifold (54) of said die (50), through an extrusion slot of said extrusion die and onto a substrate to form a coating layer on said substrate, and rapidly removing said fugitive liquid from said coating while maintaining said coating composition in said coating layer in an undisturbed condition until said coating solidifies.
  • the present invention further provides a process for forming a coating from a flocculating coating composition for an electrophotographic imaging member comprising organic pigment particles dispersed in a solution of a film-forming binder dissolved in a fugitive liquid carrier, transporting said coating composition from a pump through a mixing device, through an inlet (52) of an extrusion die (50), through a manifold (54) of said die (50), through an extrusion slot of said extrusion die and onto a substrate, subjecting said coating composition to a pressure drop of at least 68.95 kPa (10 psi) across said mixing device immediately prior to transporting said coating composition through said inlet of said extrusion die, maintaining said coating composition in turbulent flow under shear conditions having an average value of at least 10 s -1 while transporting said coating composition through said inlet of an extrusion die, through said manifold of said die, through said extrusion slot of said extrusion die and onto said substrate to form a coating layer on said substrate, maintaining the residence time of
  • the process of the present invention may be employed to coat the surface of support members of various configurations including webs, sheets, plates, drums, and the like.
  • the support member may be flexible, rigid, uncoated, precoated, as desired.
  • the support members may comprise a single layer or be made up of multiple layers.
  • Die assembly 10 comprises a die body 12 equipped with clamping flanges 14 and 16. Die body 12 comprises and upper body 18 and lower body 20 which are spaced apart to form a flat narrow passageway 22 (see FIG. 2). Passageway 22 is fed a coating composition which enters die body 12 through inlet 24 and is transported through manifold 25 and through passageway 22 to exit slot 26 through which the coating composition is extruded as a ribbon-like stream onto a moving web substrate (not shown).
  • the width, thickness, and the like of the ribbon-like stream can be varied in accordance with factors such as the viscosity of the coating composition, thickness of the coating desired, and width of the web substrate on which the coating composition is applied, and the like.
  • End dams 30 and 32 are secured to the ends of upper body 18 and lower body 20 of die body 12 to confine the coating composition within the ends of die body 12.
  • the length of passageway 22 should be sufficiently long to also ensure laminar (or streamline) flow. Control of the distance of exit slot 26 from the substrate to be coated enables the coating composition to bridge the gap between the exit slot 26 and the moving substrate depending upon the viscosity and rate of flow of the coating composition.
  • Clamping flanges 14 and 16 contain threaded holes into which set screws 40 and 42 are screwed to secure end dams 30 and 32 against the open ends of die body 12. Any suitable means such as screws 43, bolts, studs, or damps (not shown) or the like, may be utilized to fasten upper body 18 and lower body 20 together.
  • FIGS. 3 and 4 a die assembly embodiment of this invention 50 is shown. It is similar in shape to the die assembly shown in FIGS 1 and 2 except for the size and shape of the inlet 52, manifold 54 and passageway 56.
  • the cross sectional area of the inlet 52 has been markedly reduced.
  • Manifold 54 has a very small circular cross-sectional shape instead of the large tear drop cross-sectional shape of the manifold 25 shown in FIG. 2. Reduction of the cross-sectional area of the inlet 52 and manifold 54 also reduces the residence time of the coating material in the extrusion die. These changes prevent the flocculation of pigment particles dispersed in a liquid carrier.
  • particles of benzimidazole perylene tends to flocculate from dispersions at low shear conditions. It should be noted, however, that some dispersed particulate materials do not regulate or flocculate at low shear conditions.
  • An example of particulate materials that form relatively stable dispersions that do not flocculate at low shear conditions include, for example, inorganic trigonal selenium particles.
  • FIG. 5 illustrates a conventional arrangement where a coating composition is supplied from a reservoir (not shown) through line 60 to a conventional pump 62 or other suitable well known means such as a gas pressure system (not shown) which feeds the coating composition under pressure through a feed line 64 to the inlet 66 of the die body 68.
  • a conventional pump 62 or other suitable well known means such as a gas pressure system (not shown) which feeds the coating composition under pressure through a feed line 64 to the inlet 66 of the die body 68.
  • FIG. 6 illustrates a similar arrangement except that a needle valve 70 is placed in the feed line 64 between pump 62 and inlet 66 of the die body 68.
  • the needle valve is adjusted to obtain a pressure drop in the flowing coating composition as it passes through needle valve 70.
  • the imposed pressure drop imparts energy to the coating compostion and further breaks-up any flocculation.
  • Needle valve 70 is adjustable to compensate for different conditions such a change in coating composition viscosity.
  • the mixing value is operated with a pressure drop such that the shear rate in the value is greater than 100 s -1 .
  • any suitable rigid material may be utilized for the main die body.
  • Typical rigid materials include, for example, stainless steel, chrome plated steel, ceramics, or any other metal or plastic capable of maintaining precise machining tolerances.
  • Stainless steel and plated steel having a nickel plated intermediate coating and a chrome plated outer coating are preferred because of their long wear characteristics and capability of maintaining precise machining tolerances.
  • the main die body may comprise separate top and bottom sections. To achieve the extremely precise coating thickness profiles and exceptional surface quality requirements desired for electrophotographic imaging member coatings, the finish grinding of the die should be accomplished consistently under high tolerance constraints across the entire die width, e.g. widths as high as 155 cm (60 inches).
  • any suitable coating composition may be applied to a substrate with the extrusion die in this invention.
  • the coating composition comprises pigment particles dispersed in a solution of a film-forming binder dissolved in a fugitive liquid carrier.
  • Any suitable liquid carrier may be utilized.
  • a liquid carrier is a solvent for the film-forming binder utilized in the coating mixture.
  • the fugitive liquid carrier may be a solvent which dissolves the film-forming polymer.
  • Typical solvents or liquid carriers include, for example, methylene chloride, tetrahydrofuran, toluene, methyl ethyl ketone, isopropanol, methanol, cyclohexanone, heptane, other chlorinated solvents, water, and the like.
  • Any suitable film-forming polymer may be used.
  • Typical film-forming polymers include, for example, polycarbonates, polyesters, polyvinylbutyrals, VMCH and the like. Satisfactory results are achieved when the film-forming binder is present in the final coating in an amount between 10 and 90 volume percent based on the total volume of the dried coating. Preferably, between 30 percent and 80 percent by volume of the film-forming binder is present in the dried coating.
  • any suitable organic pigment particles may be used in the coating composition.
  • Typical organic pigment particles include, for example the phthalocyaninies: hydroxy-gallium, vanadyl, titanyl, X-form metal free, etc. or the perylenes such as benzimidazole perylene and the like. Whereas satisfactory results are achieved when average pigment particle size is less than 1 ⁇ m. Preferably, the average pigment particle size is less than 0.5 ⁇ m.
  • the pigment concentration in the coating compositions utilized in the process of this invention is between 20 percent and 80 percent by volume based on the total volume of the coating composition.
  • clumps are formed in the shape of large chains or agglomerates of pigment particles. These clumps are present in the inlet, manifold and extrusion slot of die extrusion systems.
  • flocculation is avoided in the flowing mixture while it passes through the die inlet, die manifold, die slot and while it dries as a coating on coated substrate by maintaining the coating composition in a high shear flow field with and average shear rate of at least 10 s -1 with average shear rates above 50 s -1 being preferred.
  • the average shear rate at entrance to a die slot with a prior art is about 2 s -1 or less.
  • the typical average shear rate at the entrance to a die slot in the process of this invention is 120 s -1 .
  • the flow history of the dispersion utilized in the process of this invention has a shear rate at least 50 s -1 .
  • Shear thinning a non-newtonian condition
  • Shear can be measured with the aid of a rheometer.
  • rheometers comprise a cup containing the dispersion to be measured and a rotating cylinder immersed in the dispersion.
  • flocculation occurs, clumps of pigment material are visible to the naked eye.
  • the clumps have a three dimensional network structure whereas non-newtonian dispersions have a two dimensional structure.
  • Shear thinning dispersions possess a yield point Under the coating conditions utilized in the process of this invention, the dispersions are subjected to sufficient shear thinning to maintain the dispersion above the yield point.
  • the size of the dumps prior to exceeding the yield point have an average size of 200 ⁇ m or greater whereas the average particle size and coating compositions maintained above the yield point have an average particle size of 10 ⁇ m or less.
  • the coating compositions utilized in the process of this invention are also subjected to a pressure drop across a mixing valve of at least 68.95 kPa (10 psi).
  • a typical inlet channel has the cross-sectional area of less than 0.5 mm. Typical inlet channel lengths range from several millimeters to many centimeters long.
  • the coating dispersion in this invention is subjected to intense shearing through the extrusion die to the point where the dispersion emerges from the extrusion nozzle.
  • the coating formed by the extrusion process is maintained in an undisturbed condition while the solvent is removed. Because of the power law index and yield point, the particles and coatings freshly formed by the process of this invention do not associate and form agglomerates because the liquid carrier is removed before such agglomeration can occur. Thus, it is also important that the applied coating dry prior to formation of dumps.
  • the use of a highly volatile fugitive liquid carrier facilitates avoidance of clumping.
  • a "streaky/mottle" band pattern can occasionally form in the coating in the region immediately opposite the point where the inlet channel joins the die manifold.
  • a means to create a high pressure drop positioned between the coating dispersion supply reservoir and the inlet channel into die manifold is desirable. Any suitable means to create a high pressure drop over a short distance and an average shear rate of at least 100 s -1 may be utilized. Typical means to create a pressure drop include, for example, needle valve and orifice plate, ball valve, jet nozzle, short capillary tube, and the like.
  • Needle valves are particularly preferred because they are adjustable to accommodate changes in concentration of the pigment, distance, coating mixture of viscosity and the like. Devices that create a pressure drop are also associated with high average shear rates. However, a static mixer such as employed in US-A-5,273,583 does not produce an average shear rate of greater than 20 s -1 .
  • the selection of the narrow die passageway and exit slot height generally depends upon factors such as the fluid viscosity, flow rate, distance to the surface of the support member, relative movement between the die and the substrate and the thickness of the coating desired. Generally, satisfactory results may be achieved with narrow passageway and exit slot heights between 75 ⁇ m and 400 ⁇ m. Good coating results have been achieved with slot heights between 100 ⁇ m and 200 ⁇ m. Optimum control of coating uniformity and edge to edge contact are achieved with slot heights between 125 ⁇ m and 150 ⁇ m.
  • the roof, sides and floor of the narrow die passageway should preferably be parallel and smooth to ensure achievement of laminar flow.
  • the gap distance between the die outer body surface adjacent to the exit slot and the surface of the substrate to be coated depends upon variables such as viscosity of the coating material, the velocity of the coating material and the angle of the narrow extrusion passageway relative to the surface of the support member. Generally speaking, a smaller gap is desirable for lower flow rates. Regardless of the technique employed, the flow rate and distance should be regulated to avoid splashing, dripping, puddling and doctoring of the coating material.
  • the flow velocities or flow rate per unit width of the narrow die passageway for the ribbon-like stream of coating material should be sufficient to fill the die to prevent dribbling and to bridge the gap as a continuous stream moves to the surface of the substrate.
  • the flow velocity should not exceed the point where non-uniform coating thicknesses are obtained due to splashing or puddling of the coating composition. Varying the die to substrate surface distance and the relative die to support member surface speed will help compensate for high or low coating composition flow velocities.
  • the coating technique of this invention can accommodate an unexpectedly wide range of coating compositions viscosities from viscosities comparable to that of water to viscosities of molten waxes and molten thermoplastic resins.
  • lower coating composition viscosities tend to form thinner wet coatings whereas coating compositions having high viscosities tend to form thicker wet coatings.
  • wet coating thickness will form thin dry coatings when the coating compositions employed are in the form of solutions, dispersions or emulsions.
  • the pressures utilized to extrude the coating compositions through the narrow die passageway depends upon the size of the passageway and viscosity of the coating composition.
  • any suitable temperature may be employed in the coating deposition process. Generally, ambient temperatures are preferred for deposition of solution coatings. However, higher temperatures may be necessary for depositing coatings such as hot melt coatings.
  • a coating composition was prepared containing about 280 g of an organic photoconductive perylene pigment having a particle size of about 0.2 ⁇ m, about 320 g of polycarbonate binder resin, and about 9400 g of a volatile solvent. This composition had a viscosity of about 105 mPa ⁇ s (cp) and was applied by means of an extrusion die (similar to the die illustrated in FIGS. 1 and 2) to a metalized polyethylene terephthalate film coated with a polyester coating.
  • the extrusion die design incorporated an inlet diameter of 12.7 mm (0.5 inch), a manifold diameter of 18 mm (0.71 inch) and passageway height of 0.127 mm (0.005 inch).
  • the geometric average shear rate was 2 s -1 or less, the residency time of the coating composition was approximately 16 s and the flow rate of 200 cm 3 /min in the extrusion die.
  • the film was transported beneath the die assembly at about 21 m/min.
  • the length, width, and height of the narrow extrusion passageway in the die was about 28 mm, 410 mm, and 0.127 mm respectively.
  • the deposited coating was dried in a multizone dryer with a maximum temperature of 143 °C.
  • the deposited dried coating exhibited a visible non-uniform mottle pattern resembling brush marks as well as streaks and dark spots.
  • Example I The procedures described in Example I were repeated except that a different die design was employed (similar to the die illustrated in FIGS. 3 and 4).
  • the extrusion die design incorporated an inlet diameter of 4.8 mm (0.19 inch), a manifold diameter of 4.8 mm (0.1875 inch), and passageway height of 0.127 mm (0.005 inch).
  • the geometric average shear rate at the inlet to the manifold was 100 s -1 or higher, the residency time of the coating composition was 2.6 s and the flow rate was 200 cm 3 /min in the extrusion die.
  • the film was transported beneath the die assembly at about 21 m/min.
  • the length, width, and height of the narrow extrusion passageway in the die was about 28 mm, 410 mm, and 0.127 mm respectively.
  • the deposited coating was dried in a multizone dryer at a maximum temperature of 143 °C.
  • the deposited dried coating exhibited no visible brush marks, streaks or dark spots except at the center of the coating opposite the die inlet. At the center of the coating, a "streaky/mottle" band, 5 -10 cm wide was observed. This defect was resolved as in example III.
  • Example II The procedures described in Example II were repeated except that a needle valve was installed in the feed line at the inlet of the die.
  • the needle valve was adjusted to achieve a pressure drop across the valve of 68.95 kPa (10 psig).
  • the deposited dried coating exhibited neither visible brush marks, streaks or dark spots, nor a "streaky/mottle" band immediately opposite the inlet to the die.
  • the extrusion die design incorporated an inlet diameter of 12.7 mm (0.5 inch) a manifold diameter of 18 mm (0.71 inch), and passageway height of 0.127 mm (0.005 inch).
  • the geometric average shear rate was 2 s -1 or less, the residency time of the coating composition was approximately 16 s and the flow rate of 200 cm 3 /min in the extrusion die.
  • the film was transported beneath the die assembly at about 21 m/min.
  • the length, width, and height of the narrow extrusion passageway in the die was about 28 mm, 410 mm, and 0.127 mm. respectively.
  • the deposited coating was dried in a multizone dryer with a maximum temperature of 143 °C.
  • the deposited dried coating exhibited a visible non-uniform mottle pattern resembling brush marks as well as streaks and dark spots.
  • Example IV The procedures described in Example IV were repeated except that the die design from Example II was employed (similar to the die illustrated in FIGS. 3 and 4).
  • the film was transported beneath the die assembly at about 21 m/min.
  • the length, width, and height of the narrow extrusion passageway in the die was about 28 mm, 410 mm, and 0.127 mm respectively.
  • the deposited coating was dried in a multizone dryer at a maximum temperature of 143 °C.
  • the deposited dried coating exhibited no visible brush marks, streaks or dark spots except at the center of the coating opposite the die inlet. At the center of the coating, a "streaky/mottle" band, 5 - 10 cm wide was observed. This defect was resolved as in Example VI.
  • Example V The procedures described in Example V were repeated except that a needle valve was installed in the feed line at the inlet of the die.
  • the needle valve was adjusted to achieve a pressure drop across the valve of 68.95 kPa (10 psig).
  • the deposited dried coating exhibited neither visible brush marks, streaks or dark spots, nor a "streaky/mottle" band immediately opposite the inlet to the die.

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  • Application Of Or Painting With Fluid Materials (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Coating Apparatus (AREA)
  • Paints Or Removers (AREA)

Claims (10)

  1. Procédé de formation d'un revêtement à partir d'une composition de revêtement qui flocule comprenant des particules de pigment dispersées dans une solution d'un liant filmogène dissous dans un support liquide fugace, en maintenant ladite composition de revêtement en écoulement turbulent sous des conditions de cisaillement moyennes d'au moins 10s-1, tout en transportant ladite composition de revêtement au travers d'une entrée (52) d'une filière d'extrusion (50), au travers d'un collecteur (54) de ladite filière (50), au travers d'une fente d'extrusion de ladite filière d'extrusion et jusque sur un substrat afin de former une couche de revêtement sur ledit substrat, et en éliminant rapidement ledit liquide fugace dudit revêtement tout en maintenant ladite composition de revêtement dans ladite couche de revêtement à un état non perturbé jusqu'à ce que ledit revêtement se solidifie.
  2. Procédé selon la revendication 1, comprenant l'exposition de ladite composition de revêtement à des conditions de cisaillement moyennes d'au moins 50 s-1 tout en transportant ladite composition de revêtement au travers de ladite filière d'extrusion.
  3. Procédé selon la revendication 1 ou 2, comprenant le maintien du temps de séjour de ladite composition de revêtement dans ladite filière d'extrusion à moins de 5 s, ou le maintien du temps de séjour de ladite composition de revêtement dans ladite filière d'extrusion à moins de 3 s.
  4. Procédé selon l'une quelconque des revendications 1 à 3, comprenant l'exposition de ladite composition de revêtement à une chute de pression d'au moins 68,95 kPa (10 livres/pouce carré) dans un dispositif de mélange immédiatement avant le transport de ladite composition de revêtement au travers de ladite entrée (52) de ladite filière d'extrusion (50), ou l'exposition de ladite composition de revêtement a une chute de. pression d'au moins 137,90 kPa (20 livres/pouce carré) dans un dispositif de mélange immédiatement avant le transport de ladite composition de revêtement au travers de ladite entrée de ladite filière d'extrusion.
  5. Procédé selon la revendication 4, comprenant la création de ladite chute de pression en faisant passer ladite composition de revêtement au travers d'une vanne à aiguille, ou la création de ladite chute de pression en faisant passer ladite composition de revêtement au travers d'un orifice, ou la création de ladite chute de pression en faisant passer ladite composition de revêtement au travers d'un éjecteur, ou la création de ladite chute de pression en faisant passer ladite composition de revêtement au travers d'un court tube capillaire.
  6. Procédé selon l'une quelconque des revendications 1 à 5, dans lequel ledit collecteur (54) de ladite filière d'extrusion (50) présente une forme de section transversale circulaire.
  7. Procédé selon l'une quelconque des revendications 1 à 6, dans lequel la concentration desdites particules de pigment dans ladite composition de revêtement se situe entre 20 pour cent et 80 pour cent en volume sur la base du volume total de ladite composition de revêtement.
  8. Procédé selon l'une quelconque des revendications 1 à 7, dans lequel lesdites particules de pigment présentent une taille moyenne de particules de moins de 1 µm durant le transport de ladite composition de revêtement au travers de ladite entrée, au travers dudit collecteur, au travers de ladite fente d'extrusion et jusque sur ledit substrat afin de former ladite couche de revêtement.
  9. Procédé selon la revendication 7, dans lequel lesdites particules de pigment comprennent un pigment organique convenant à une utilisation de photorécepteurs tels que les pérylènes et les phthalocyanines.
  10. Procédé de formation d'un revêtement à partir d'une composition de revêtement qui flocule destinée à un élément de formation d'image électrophotographique comprenant des particules de pigment organique dispersées dans une solution d'un liant filmogène dissous dans un support liquide fugace, en transportant ladite composition de revêtement provenant d'une pompe au travers d'un dispositif de mélange, au travers d'une entrée (52) d'une filière d'extrusion (50), au travers d'un collecteur (54) de ladite filière (50), au travers d'une fente d'extrusion de ladite filière d'extrusion et jusque sur un substrat, en soumettant ladite composition de revêtement à une chute de pression d'au moins 68,95 kPa (10 livres/pouce carré) dans ledit dispositif de mélange immédiatement avant le transport de ladite composition de revêtement au travers de ladite entrée de ladite filière d'extrusion, en maintenant ladite composition de revêtement en écoulement turbulent sous des conditions de cisaillement présentant une valeur moyenne d'au moins 10 s-1, tout en transportant ladite composition de revêtement au travers de ladite entrée d'une filière d'extrusion, au travers dudit collecteur de ladite filière, au travers de ladite fente d'extrusion de ladite filière d'extrusion et jusque sur ledit substrat afin de former une couche de revêtement sur ledit substrat, en maintenant le temps de séjour de ladite composition de revêtement dans ladite filière d'extrusion à moins de 5 s, et en éliminant ledit liquide fugace dudit revêtement avant l'agglomération desdites particules de pigment organique tout en maintenant ladite composition de revêtement dans ladite couche de revêtement à un état non perturbé jusqu'à ce que ledit revêtement se solidifie.
EP96300063A 1995-01-03 1996-01-03 Procédé de revêtement par extrusion Expired - Lifetime EP0720873B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US368129 1995-01-03
US08/368,129 US5516557A (en) 1995-01-03 1995-01-03 Method for applying a flocculating coating composition including maintaining turbulent flow conditions during extrusion

Publications (3)

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EP0720873A2 EP0720873A2 (fr) 1996-07-10
EP0720873A3 EP0720873A3 (fr) 1998-12-16
EP0720873B1 true EP0720873B1 (fr) 2002-05-02

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EP (1) EP0720873B1 (fr)
JP (1) JP3810839B2 (fr)
DE (1) DE69620922T2 (fr)

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US7559990B2 (en) * 1998-05-19 2009-07-14 Eugene A Pankake Coating apparatus and method
US6057000A (en) * 1998-10-29 2000-05-02 Xerox Corporation Extrusion coating process
US20090295098A1 (en) * 1999-05-18 2009-12-03 Pankake Eugene A Coating apparatus and method
US20030215581A1 (en) * 2002-05-20 2003-11-20 Eastman Kodak Company Polycarbonate films prepared by coating methods
US20060024445A1 (en) * 2004-07-28 2006-02-02 Xerox Corporation Extrusion coating system
JP2015178050A (ja) * 2014-03-18 2015-10-08 日東電工株式会社 塗工装置及び塗工膜の製造方法

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Also Published As

Publication number Publication date
EP0720873A3 (fr) 1998-12-16
DE69620922T2 (de) 2002-08-29
JP3810839B2 (ja) 2006-08-16
US5516557A (en) 1996-05-14
JPH08229496A (ja) 1996-09-10
DE69620922D1 (de) 2002-06-06
EP0720873A2 (fr) 1996-07-10

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